Vasoreactions to acute hypoxia, whole lungs and isolated vessels compared: modulation by NO
| Autor: | X Liu, G.R Barer, G.-Q Teng, C.J Emery |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Pulmonary and Respiratory Medicine
Male Pulmonary Circulation Time Factors Physiology Pharmacology In Vitro Techniques Nitric Oxide Nitric oxide chemistry.chemical_compound Hypoxic pulmonary vasoconstriction Potassium Channel Blockers Medicine Animals Rats Wistar Hypoxia Lung business.industry General Neuroscience Myography Hypoxia (medical) medicine.disease Pulmonary hypertension Rats medicine.anatomical_structure NG-Nitroarginine Methyl Ester chemistry Vasoconstriction Anesthesia Circulatory system sense organs medicine.symptom Nitric Oxide Synthase business Blood vessel |
| Zdroj: | Respiratory physiologyneurobiology. 134(2) |
| ISSN: | 1569-9048 |
| Popis: | We aimed to explain diverse pulmonary vascular responses to hypoxia in different preparations and their modulation by NO. In rats we compared isolated perfused lungs (IPL), small vessels in vitro (PRVs) and in vivo preparations. In IPL and in vivo, acute and chronic nitric oxide synthase (NOS) blockade with L-NAME left normoxic pulmonary artery pressure unchanged but enhanced hypoxic vasoconstriction, hypoxia-induced pulmonary vasoconstriction (HPV). PRVs in vitro, precontracted with PGF(2alpha), showed four tension changes in acute hypoxia: dilatation, contraction, dilatation, contraction. Acute and chronic NOS blockade reduced the first two phases. In non-precontracted PRVs (from other laboratories), NOS inhibition enhanced HPV as in vivo and IPL; attenuation of HPV seems associated with precontraction. Thus reduced NOS activity does not cause pulmonary hypertension but exaggerates HPV. In IPL, prolonged severe hypoxia caused biphasic vasoconstriction separated by dilatation; the time course resembled that seen in PRVs. We suggest that the sequence of events during hypoxia in PRVs can be detected in whole lung preparations. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect